REDARC SMART START

"The new Mosfets are military grade and have no voltage drop"

Derek would you elaborate on this please?

ed

Hi Thylacine

A Mosfet is a electronic switch also know as a gate. They are widely used in almost all electronic products to switch them on and off. Plasma TV's, Audio equipment, computers, etc. They offer a clean on / off solution to sensitive electronic devices. You may remember older radio's that turned on with a switch and they would crackle and spike. New radio's and tv's fitted with mosfets are switched on without noises, crackles and spikes.

Our Mosfets are large units of the above and are capable of switching very large loads with no burnt contacts, faulty solenoids, moving parts, corrosion or most important voltage drop.

They are new being introduced into winch controllers as they are reliable and waterproof.

www.jeephorizons.com/news/images/06_sema/milemarker_mx9.jpg

The ones used in our BiSolator have been used for DC switching of high current loads on fork lifts, loading platforms, telecommunications and electric vehicles.

Think of a Mosfet as a solid state solenoid. Here is a basic picture of the principal of a Mosfet. Mosfets are quite complex and there are many types.



I hope this explains it a bit for you, I have tried to make it as simple as possible.

Regards

Derek.

I will try another picture of the MOSFET winch.

Ta Derek, but I'm actually pretty clued-in on semiconductor basics (Control Systems engineer for 20+ yrs).
What I was interested in was the "no voltage drop" statement (and calling them "our mosfets" is a bit cheeky).
Would you mind posting the specs of these mosfets please.

ed

Hi Ed

I did not realise you already knew what a MOSFET is.

No I will not be posting my specs or internal circuits of our BiSolator as they can easily be copied.

Our test at 13.8 Volts and 20 amp current showed a differing voltage between source and load of 0.016 volts.

Solenoid type Smart Relays show an average of 0.5 v drop.

Regards

Derek.

Mate I didn't ask for a circuit diagram. Just the specs for the mosfet you are using. This is akin to asking Toyota what size/type tyre fits a landcruiser.
It's not as if you designed or made them, and anyone with enough knowledge to understand the specifications would be more than capable of designing their own dual battery system. We are, after all, talking very simple circuitry.
Starting to look like another case of "baffle them with bull bleep ".
Please prove me wrong, as there is far too much of this going on in the 4WD electrics area.

ed

Hi Ed

I thought that was where you were heading and won't get into this type of thread.

Hi Ed

Here is the last thread you answered to the same questions you have.

PostID: 41421

Regards

Derek.

I'll tell you what.
You stop making fantastical claims, and I'll stop querying them.
You promote your units specifically stating the benefits of mosfet design, yet refuse to offer the specs on such.
I'm not into arguing for the sake of it, but am sick of salespeople mis-representing their products. This is rife with dual battery controllers, and often coupled with enough technical terms to convince a layman that they're getting advice from someone who knows what they are talking about.

ed

Hi Ed

I have in your previous thread made you an offer to test a unit free of charge.

"Why not send me your email address and when they arrive you can test one for a few weeks. I plan to have test modules for people to try out and then return if not happy. "

to which you answered.

"Thanks for the offer Derek, but no thanks, for several reasons.
Firstly I can't see the point in a few-week test, or a few-month for that matter.
Secondly, If it has more electronic components than diodes, bush fault-finding becomes difficult. And looking at your pic of the unit it's set in resin so irreparable anyway. I'd have to know it's principle of operation (and be happy with it) before thinking of trusting it.
This is the reason I stick with a simpler system (and drive an old landcruiser) - I can fix most things that break in the bush.
cheers, "

We have done our own extensive tests on the ability of the product to carry the specified loads and compared these to the manufacturers specifications prior to ordering and manufacturing these BiSolators. They perform perfectly and are covered by a full exchange warranty.

We are the Australian Distributor and have stock holdings to service the 4wd and marine market.

2 models are available. 80A Constant with 160A surge and our big unit 150A with 300A surge. These are alternator currents and both units have current limiting protection. The automatic start boost feature is included in both units.

Yes they are set in resin for marine and heavy 4wd applications.

Regards

Derek.

The specifications are on my site if needed.

>A Mosfet is a electronic switch also know as a gate

In over 30 years in the electrical/electronics design field I have never, ever
heard a MOSFET or any type of FET called "a gate". The gate is the control terminal of the device.

>Our test at 13.8 Volts and 20 amp current showed a differing
>voltage between source and load of 0.016 volts.

What range of temperatures were your tests performed over Derek?

>You stop making fantastical claims, and I'll stop querying them.

You should see what he says you can do to AGM batteries! :) Still waiting for a manufacturers reference on that one btw Derek?

>2 models are available. 80A Constant with 160A surge and our
>big unit 150A with 300A surge.

How do these units react in the event of an impulse current above the specifications?

One of the big advantages of relays is that they will accept severe abuse without failing, semiconductors are much less able to do that and MOSFETs, because of their extremely high input impedance are also far more susceptible to noise causing rogue switching.

Thylacine: the best RDS(on) I have seen in recent times is about 10mR typical at 25C, there may be better ones but they would be quite expensive.

Mike Harding
[Who's designed a few things with MOSFETs in them over the years]

Hello Mike

“In over 30 years in the electrical/electronics design field I have never, ever
heard a MOSFET or any type of FET called "a gate". The gate is the control terminal of the device.”

No, the gate is the gate and the gate has a terminal ! Not everyone is a rocket scientist.

MOSFET

metal-oxide-semiconductor field-effect transistor

The 'metal' in the name is often incorrect as current process technologies usually use polysilicon gates. Some prefer to use "IGFET" when referring to devices with polysilicon gates. When a voltage is applied between the gate and source terminals, the electric field generated penetrates through the oxide and creates a so-called "inversion channel" in the channel underneath. it provides a conduit through which current can pass. Varying the voltage between the gate and body modulates the conductivity of this layer and makes it possible to control the current flow between drain and source.

“What range of temperatures were your tests performed over Derek?”

If you check our specifications the test was done at 20 deg C.

“You should see what he says you can do to AGM batteries! :) Still waiting for a manufacturers reference on that one btw Derek?”

Lifeline batteries are a C4 rating (max charge rate is 25% of capacity) 100 a/h battery = 25 amps max charge rate.

Fullriver batteries are a C5 rating (max charge rate is 20% of capacity) 100 a/h battery = 20 amps max charge rate.

MK Batteries are a C3 rating (max charge rate is 30% of capacity) 100 a/h battery = 30 amps max charge rate.

Here is their company website. www.mkbattery.com/index.php

Here is their AGM technical manual. http://www.mkbattery.com/images/VRLA_TechManual.pdf

Here is their charge guide lines. http://www.mkbattery.com/images/AGMBatteryCharging.pdf

“How do these units react in the event of an impulse current above the specifications?”

They have built in current limiting.

“One of the big advantages of relays is that they will accept severe abuse without failing, semiconductors are much less able to do that and MOSFETs, because of their extremely high input impedance are also far more susceptible to noise causing rogue switching.”

How long have you been retired ?

There is new technology and modern MOSFET’s are stable and used in most high end electronic products.

I thought better of you Mike.

Here is one for you….

Optima AGMs are claimed (Not by me) to fully recharge in 1 hour.

>>What range of temperatures were your tests performed over Derek?”

>If you check our specifications the test was done at 20 deg C.

In that case it's meaningless. Automotive parts should be qualified, iirc, at -40C and +105C, _especially_ for underbonnet use. The major automotive designers (Bosch etc) don't even accept the manufacturers data they do their own qualification on _every_ _single_ _device_ they use and no devices which have not received their "automotive qualification" are permitted to be used in a product of their worldwide organisation. Last I heard it cost about A$30k to qualify a part at Bosch. Makes for very expensive resistors.

The Fullriver data sheet I gave you a link to specs. 20A (or something, can't remember) as the max initial charge current - are you suggesting it's wrong?

>They have built in current limiting.

Really. I'm only aware of two ways to measure DC current; shunt voltage and Hall Effect and if you're using a shunt then you'll counteract the advantage of the low RDS(on) of a MOSFET and would cause your product to have significant voltage drop. This is a problem with semiconductors, it's hard to protect them from overloads - they tend to blow up. What are the overcurrent specifications for your product Derek? Is it capable of withstanding a source of 1000A for 50mS at 105C? How about overvoltage? What can it handle there? Mercedes have a spec. requiring modules to withstand 120V for 300mS can you product handle that? Spikes into the hundreds of volts are common - you have a spec for that too, do you?

>>“One of the big advantages of relays is that they will accept
>>severe abuse without failing, semiconductors are much less
>>able to do that and MOSFETs, because of their extremely
>>high input impedance are also far more susceptible to noise
>>causing rogue switching.”

>How long have you been retired ?

Still working Derek. In fact you'll find some of my design work in the new Holden VE Commodore.

>There is new technology and modern MOSFET’s are stable and
>used in most high end electronic products.

MOSFETs!!??? New technology!!!??? You make me laugh. I was designing stuff with MOSFETs when you were wondering what the difference between current and voltage was.

>I thought better of you Mike.

Derek, it is clear to me that you are an amateur masquerading as a professional, you are a salesman, not an engineer, and frequently use this forum to push your products. I'll give you a little advice Derek: make damn sure you get both the design (including EMC emissions and susceptibility) and full environmental testing of your product right otherwise you'll have more returns than you can poke a stick at. After military/space and medicine the automotive market is the most demanding environment to design for and babes in the wood who try it often end up bankrupt. Getting a few products to work is gentle environments is a whole different game to getting high volume production to work in the real world.

Derek: there are a few people, nowadays, on this forum who really know what they are talking about when it comes to electronic design: you are not one of them.

Mike Harding

Dear Mike

The specification sheet is supplied by the manufacturer and 20 deg C is their foot note and seems to be an industry standard including Blue Sea Systems and Cole Hersee. My independent test temperatures are not on the manufacturer’s specification sheet and was done at normal operating temperatures. The units are fitted with heat sinks to keep the temperature low and have no derating from -40 to + 85 deg C.

I did not accept the data at face value and that is why I tested these units for 6 months prior to manufacture.

The Fullriver Data sheet was the DC100-12B and yes initial current was 20A yes. (C5)

Our unit has a 105 deg peak of 600 amps @ 50ms and recommend 2 parallel units to obtain 1000 amps or more if needed. It is unlikely that more then that will be needed on most vehicles with the exception of large diesels and high compression engines. Most vehicles are now fitted with reduction starter motors and cranking amps are with-in specification.

Surges and spikes are controlled by the internal circuit and yes spikes up to 100V are common and easy controlled. I have not seen spike go into hundreds of volts. The microprocessor controls the switch ON rise-time to limit inrush currents during first 2 ms and switch OFF is also controlled.

The units are rated 9 to 30 volts and have full CE approval.

I would be interested in your design work for the VE Commodore.

I know Mosfet’s have been around a long time I used them in the 80’s. They have been improved and are commonly used. I did not try to imply they are a new invention but are not what they used to be or even made the same. Please read what I said again ‘There is new technology and modern MOSFET’s are stable and used in most high end electronic products.’

I won’t comment on your last paragraph but find it insulting. I apologise for assuming you were retired.

Have a good weekend.

Regards

Derek.

Thanks for yor input Derek, much appreciated

Guys that all went over my head but was very entertaining I feel like I just red book from cover to cover ...how about you all just kiss and make up I think you would both get on great as you both have the same interest and seem very passionate about electronics ??? well I'm going to go pour my self a scotch and I hope when I come back you boys have shaken hands and made up ..LOL

Regards J.B.

HEAR HEAR!!!!!!!!!!!!!!!!!!!!

Spot on, HEAR, HEAR, HEAR, !!!!!!!!!!!!!!!!!

Thanks Leigh that was what I was after, Im not too technical minded but can usually work things out. I havent had much of a play but I presume you just ran a wire from the black earth wire to your switch then back to earth. Thanks for your help